GRMS Options

[Eighteen11R]

Looking for best-of findings here for my decision to go with GRMS for Mobile Comms. FCC paid, Callsign issued. Set package arrival this morning.

Has anyone had any experience with antenna switching devices? Wondering if the 3dB NMO up top or out front and a 6dB NMO out back are a viable option? Should I just go single position with antenna swaps when/if necessary?

Cheers mates,
G

 

[bamabrock]

I use the Midland 40w with 6db antenna. Not sure if dual antenna are needed or would be able to be properly tuned.

 

[Eighteen11R]

I use the Midland 40w with 6db antenna. Not sure if dual antenna are needed or would be able to be properly tuned.

Where did you mount your 6dB antenna? Any pics?

 

[OwnerCS]

I run the MXT275 with the Alamosa 6db gain antenna on the ARB bumper's bar light tab. I need to run the radio on "low power" when I'm in a group of other radios. Before I switched to low power, the other radios could not cope with the high power. I plan to use high power this weekend when I know I will be many miles away from the other radio.

 

[Pskhaat]

Looking for best-of findings here for my decision to go with GRMS for Mobile Comms. FCC paid, Callsign issued. Set package arrival this morning.

View attachment 2775385

Has anyone had any experience with antenna switching devices? Wondering if the 3dB NMO up top or out front and a 6dB NMO out back are a viable option? Should I just go single position with antenna swaps when/if necessary?

Cheers mates,
G

What will you be switching? Automatically between the two? Manual if you want one vs. the other?

 

[Eighteen11R]

What will you be switching? Automatically between the two? Manual if you want one vs. the other?

Thanks for the question @Pskhaat, probably manual as I was thinking since I have purchased both the 3dB Ghost and the 6dB whip antennas, mounting both on the rig with consideration to use one or the other (via a switch) depending on your reach/receive requirements...?

Our Club Radio Sherpa advises "the top center of the roof is the best, but usually unpractical. Ideally the antenna wants a 360 view and a ground plane. For the UHF GMRS freqs the ground plane should be at least an 7 inch diameter sheet of metal with the antenna mount in the center."

I have a Rhino Rack Pioneer Platform overhead for it's low profile.

I also purchased the Rhino Rack folding antenna mount for my original CB radio set up that I'm now selling...

SOLD - VA - UNIDEN CMX760 (NIB) CB Package

Made the decision to go GMRS so my procrastination is your gain... Everything is here to make your CB Comms dreams come true. The package includes a 2' FireStik II tunable 5/8 wave antenna (Blue), a FireStik medium duty stainless steel spring, and 18' of the FireStik K8A coax cabling. The...

forum.ih8mud.com

Wondering if this mount could be modified for GRMS use or should I let it go with the Uniden/FireStik CB package.

Will the RR folder provide the ground plane needed for optimum performance?

If used, I'll be raising my overhead clearance number by ~80 mm when stowed/folded.

I assume Rhino Rack originally designed this folding mount for CB antenna applications so I'll have to enlarge the antenna mounting hole to ~19mm for the NMO antenna base. I found a lot of info on the NMO base here...

What is an NMO mount? - The Solid Signal Blog

It seems like no one on the internet knows why an NMO mount is called an NMO mount. Do you?

blog.solidsignal.com

I guess, when it's all said and done, a single mount, centered on my Pioneer Platform will allow low profile trail riding with the 3dB Ghost Antenna and if enhanced reach/receive are required, a quick R&R for the 6dB whip mast (~32") would be in order...?

Cheers mates,
G

 

[Pskhaat]

Our Club Radio Sherpa advises "the top center of the roof is the best, but usually unpractical. Ideally the antenna wants a 360 view and a ground plane.

All correct. But also often a dream we all can't achieve. The key is height, but we all deal with branches, foilage and other things that may make that impractical. Top center of roof is great, but I have my rooftent there. I do still park when at home in a garage, and have elected to mount on the front metal bumper. Theoretically not ideal, but I've yet to have any discernible performance issues there.

Wondering if this mount could be modified for GRMS use or should I let it go with the Uniden/FireStik CB package.

View attachment 2780691

It isn't particular to any radio band, just the way specific antennas mounts.

Will the RR folder provide the ground plane needed for optimum performance?

See above as per performance.

NMO antenna base. I found a lot of info on the NMO base here...

NMO was designed with keeping the best possible impedance match between counterpoise and the antenna. To add in only a small bit of vendor flair in here, we could not use NMO (I did try) with our radome antennas, as the moment generated by the vehicle to the aerial was too much for NMO, and therefor requiring a sturdy spring, and therefor no NMO. If you want a different approach to an antenna, check us out: Login • Instagram - http://www.instagram.com/alamosaantenna/

 

[Pskhaat]

Oh, forgot to add: a manual switch would be just fine if you wanted to keep both antennas, fairly simple Amazon product ASIN B00HYJPU8W

 

[Helipilot]

Midland farm tractor bundle x2, one on the 40 and one for the 100. You can see the mount on the 40. I can switch antennas and use the mounts for a 50 watt 2 meter as well. The tractor bundle had the tube mount included for mounting on the back rack

 

[Eighteen11R]

Midland farm tractor bundle x2, one on the 40 and one for the 100. You can see the mount on the 40. I can switch antennas and use the mounts for a 50 watt 2 meter as well. The tractor bundle had the tube mount included for mounting on the back rack

View attachment 2797651

View attachment 2797652

View attachment 2797653

View attachment 2797654

View attachment 2797655

How does your set up look in the ?

 

[Helipilot]

Just ordered all the bits and pieces from Ram Ball mounts to get the radios mounted in the 100. I will post up photos once that is finished.

I followed Jim, @jj-sc. on the Gamviti antenna mount for the 100 series that mounts the antenna on the fender. Very clean mount and a straight shot to the firewall for the coax. His setup is very nice looking on his '06.

 

[Eighteen11R]

Just ordered all the bits and pieces from Ram Ball mounts to get the radios mounted in the 100. I will post up photos once that is finished.

Have you checked out O W L-Expedition's Media Mount @Helipilot ?

Owl Expedition Media Mount - https://forum.ih8mud.com/threads/owl-expedition-media-mount.1002023/.

It's a great piece of kit as it replaces the obsolete cassette deck tape transport system...

 

[OwnerCS]

Very nice FJ40 @Helipilot

I usually go off-roading monthly in the Ouachitas and Ozarks.

I've grown to love the Alamosa mounted on the front bull bar to use as a Ozarks trail brush clearance indicator.

It helps keep me out of trouble when I get out into the ruff areas with low hanging trees and brush.

Like a cat uses whiskers to know if it can clear crawling into a hole.